The field of the present invention is V-belts and particularly V-belts of relatively inflexible materials.
V-belts have been employed in many circumstances for the transmission of power from one pulley to another. The pulleys employed have grooved peripheral surfaces for receipt of the V-belt such that the tension on the belt acts to wedge the belt into the pulley grooves for increased normal force between the groove and belt surfaces.
Typically, V-belts have been made of reinforced, highly elastic materials such as rubber. Such belts are generally continuous and uniform in cross section and provide high coefficients of friction with the pulley surfaces, relatively high power transmission and substantial longevity. However, such belts also experience large friction losses, losses due to internal hysterisis, and limitations as to power transmitted.
To avoid the failings of more elastic materials, a variety of metal belts have been devised. Such metal belts are generally link-type belts rather than continuous belts as in the case of more flexible materials. A first prior art belt is illustrated in FIGS. 1 and 2. Such a belt includes metal V-blocks which are assembled on a plurality of endless belts or metal strips. The metal strips are overlaid and set within channels formed in the metal V-blocks. Pins extend across the channels over the metal strips to retain the metal V-blocks in place.
The device illustrated in FIGS. 1 and 2 is generally subject to elongation under any significant amount of power; and torque transmission may be lost due to the play between adjacent V-blocks. Alternatively, the metal strips may be thickened to overcome the foregoing problems. However, the belt is then less flexible and will not conform to the radius of the pulley. Non-conformance of the belt to the pulley can result in variations in the drive ratio and other difficulties associated with lack of flexibility.
In another example of prior art metal V-belts, FIGS. 3 and 4 illustrate a link-type V-belt having pins connecting adjacent links. Extending through the links to opposite sides thereof are rigid plates having small, inclined end surfaces. These plates are stacked to give effective width to the inclined surfaces. The plates may be set within a bearing type material or resilient type material to enable the plates to better conform to the conical surfaces of the groove of the pulley. The resulting inclined surfaces thus formed are, by the structure of the device, generally relatively small in relation to the size of the links. As a result, low torque transmission capability is exhibited. Furthermore, as the plates are capable of moving relative to the links, internal friction is experienced resulting in low transmission efficiency.